1. Field of the Invention
The invention relates to a liquid crystal display, and more particularly, to a liquid crystal display including a frame-structure layer to improve the fixity between a display panel module and a touch panel.
2. Description of the Prior Art
A liquid crystal display is a flat display device with thin appearance and light weight. Because the typical liquid crystal display has little radiation pollution, a user can use it for a long time without eye strain. With the additional advantages of small size and low power consumption, liquid crystal displays are widely used.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram illustrating a touch liquid crystal display 10 according to the prior art, and FIG. 2 is a schematic diagram illustrating a metal housing 16 of the touch liquid crystal display 10 in FIG. 1. As shown in FIG. 1, the prior art touch liquid crystal display 10 comprises a plastic housing 12, a display panel module 14, a metal housing 16, and a touch panel 18. The plastic housing 12 comprises a base 12a and a wall 12b, and the wall 12b surrounds the base 12a. The display panel module 14 is positioned on the base 12a of the plastic housing 12. The display panel module 14 contacts the plastic housing 12, and is surrounded by the base 12a and the wall 12b. The structure of the display panel module 14 depends on the needed design of the display device. Take a panel module of a back light liquid crystal display, for example, comprising a liquid crystal panel 14a and a back light module 14b. The back light module 14b comprises a reflector, a light guide, and an optical film (not shown in the figure). The metal housing 16 comprises a covering plane 16a and a wall 16b. The covering plane 16a covers an edge of the display panel module 14, and an inner surface of the wall 16b of the metal housing 16 surrounds an outer surface of the wall 12b of the plastic housing 12. The touch panel 18 is positioned on the metal housing 16, and contacts the covering plane 16a. Users can directly enter their commands by way of the touch panel 18.
Installing the metal housing 16 in the prior art touch liquid crystal display 10 can fix the touch panel 18, and prevent electromagnetic interference. As shown in FIG. 2, an included angle 16c between the wall 16b and the covering plane 16a of the metal housing 16 is smaller than 90 degrees, so that the plastic housing 12 and the display panel module 14 are fixed within the metal housing 16. The included angle 16c of the metal housing 16 with such design becomes 90 degrees after the metal housing 16 is reworked. Besides, there is a tolerance between the metal housing 16 and the plastic housing 12. Because of the tolerance and the larger included angle 16c, the metal housing 16 and the plastic housing 12 are displaced a small amount. Additionally, there are interstices between the metal housing 16 and the plastic housing 12 after the metal housing 16 and the plastic housing 12 are combined. Particles or the foreign objects may slip into these interstices. Moreover, light of the display panel module 14 may leak out through the interstices between the touch panel 18 and the display panel module 14. Because the included angle 16c between the wall 16b and the covering plane 16a of the metal housing 16 may be larger than 90 degrees after the metal housing 16 is reworked, it is harder to fix the metal housing 16 to the plastic housing 12. Therefore, the original metal housing 16 is usually replaced by a new metal housing 16 in which the included angle 16c between the wall 16b and the covering plane 16a is smaller than 90 degrees after the metal housing 16 is reworked. Because the original metal housing 16 is replaced by a new metal housing 16, the touch panel 18 should be removed from the surface of the original metal housing 16. The touch panel 18 may be damaged when it is removed from the original metal housing 16. In other words, due to the structure of the prior art touch liquid crystal display 10, the reworking process for the prior art touch liquid crystal display 10 is difficult and complicated. Furthermore, an external force may damage the display panel module 14 if the prior art touch liquid crystal display 10 is dropped or is bumped. Because of the damage by such an external force, the operation of the prior art touch liquid crystal display 10 is influenced.
Thus, there is a need for a structure of a liquid crystal display which can prevent foreign objects from slipping into spaces between the touch panel and the display panel module, prevent light leakage, improve the fixity between the metal housing and the plastic housing, and protect the liquid crystal display from damage.